BookDAOImpl.java 文件源码

public List<BookEntity> findAll() {
    EntityManager em = connection.createEntityManager();
    List<BookEntity> result;

    try {
        em.getTransaction().begin();
        TypedQuery<BookEntity> query = em.createQuery("Select b from BookEntity b", BookEntity.class);
        result = query.getResultList();
        em.getTransaction().commit();
    } finally {
        if (em.getTransaction().isActive()) {
            em.getTransaction().rollback();
        }
        em.close();
    }

    return result;
}